To find the speed of a wave, you need two pieces of information:

1. Wavelength (λ): This is the distance between two consecutive crests (or troughs) of the wave. It's essentially the length of one complete wave cycle.

2. Frequency (f): This is the number of waves that pass a fixed point in one second. It represents how often the wave oscillates.

The formula to calculate wave speed (v) is:

v = λf

Example:

Let's say a wave has a wavelength of 2 meters and a frequency of 10 Hz.

* Wavelength (λ) = 2 meters

* Frequency (f) = 10 Hz

Using the formula, the wave speed would be:

v = λf = 2 meters * 10 Hz = 20 meters per second